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Emission Under Stress

Amorphous and microcrystalline thin-film semiconductors have had a huge impact in the field of display technology. Now technologies with even lower power consumption and with higher resolution, such as cold emitter arrays, are being pursued. Thin-film amorphous carbon is one such candidate material for this application. Electron emission can occur at low voltages, but the mechanism remains unclear.

Pau et al. have studied electron emission yield from a series of amorphous carbon thin films grown by plasma deposition possessing various levels of internal stress. Films with higher amounts of stress and larger volumes of sp2 bonding have the lowest bias at which electrons are emitted. Just as application of pressure can alter the electronic properties of materials, the authors suggest that the internal stress distorts the electronic bands within the film, resulting in enhanced electron emission at low voltages. The result may prove useful for other thin-film technologies. — ISO